Background
Much has been discussed of late in both the scientific and popular media relative to the issue of whether or not warming in certain sectors of the planet is increasing tropical cyclone (TC) intensities; and the study of Balling and Cerveny addresses this issue.

What was done
The two Arizona State University (USA) researchers examined temporal patterns in the frequency of intense TCs, the rates of rapid intensification of TCs, and the average rate of intensification of hurricanes in the North Atlantic Basin, including the tropical and subtropical North Atlantic, Caribbean Sea and Gulf of Mexico, where they say there was "a highly statistically significant warming of 0.12°C decade^-1 over the period 1970-2003 ... based on linear regression analysis and confirmed by a variety of other popular trend identification techniques."

What was learned
Balling and Cerveny report that they "found no increase in a variety of TC intensification indices," and that "TC intensification and/or hurricane intensification rates ... are not explained by current month or antecedent sea surface temperatures (despite observed surface warming over the study period)." Hence, they conclude that "while some researchers have hypothesized that increases in long-term sea surface temperature may lead to marked increases in TC storm intensity, our findings demonstrate that various indicators of TC intensification show no significant trend over the recent three decades."

What it means
Over the past three decades of significant warming of the major source region of hurricanes capable of striking the United States, there apparently has been no detectable increase in the numbers of intense hurricanes nor hurricane intensities, contrary to what so many people have been led to believe by those who see catastrophic consequences of even modest regional warming in almost every conceivable phenomenon having a connection to weather and climate.